The present invention is directed to a method of manufacturing a lining part having a viewing or front side and a back side, wherein a blank that already has its ultimate shape in the unstressed condition, but is not independently shape-stable, for example a pre-formed and/or profiled wood veneer part provided with ornaments, written characters or the like, has its back side provided with a reinforcing layer and has its viewing or front side equipped with an at least partially transparent front surface coating with optical surface qualities by injection molding composed of a chase and top flask or two molding parts. The invention is also directed to the lining part particularly manufactured according to this method, which is composed of a blank, such as a wood veneer part or the like that has its back side provided with a reinforcing layer and has its front side provided with at least a semi-transparent front side coating with an optical surface quality which has been applied by injection molding.
An earlier German Patent Application P 41 24 297 discloses a method for injection molding, wherein the edges and seams of a blank with a reinforcing layer are sealed with a front side or surface coating. Whereas it was hitherto standard to provide the viewing or front side of the lining part that, for example, is composed of a wood layer, fabric layer or foil with a back surface reinforcement with a high-gloss lacquer coating, such a lacquer coating is superfluous in the earlier proposal because the front surface coating can be simultaneously produced with optical surface quality in the injection molding process.
The previous procedure of providing a lacquer coating had comprised therein that the lacquer was applied by spraying or atomizing onto the appertaining blank from the convex sides after it had been profiled, for example by bending in order, on the one hand, to obtain a desired sealing and, on the other hand, to obtain the optimally glossy surface. Lacquers of a polyester type, for example polyurethane, were utilized. However, it was necessary in most instances to also polish the lining part after the lacquering. In addition, laterally projecting noses and spurs composed of the lacquer material must be removed.
The disadvantage of this known procedure is that there were environmental problems which occurred because the lacquer proceeds into the ambient atmosphere when sprayed. In addition, there was the problem with not protecting the edges of the wood against the penetration of moisture or the like so that a protection must be applied in an additional work step.
By comparison thereto, the above-mentioned German Application 41 24 294 was already distinguished in that the perfect sealing of the finished lining part is possible and that the environmental problems are largely avoided. In the method of the earlier proposal, a high-gloss surface that did not require any after-polishing can be produced. It is possible to achieve a completed edge protection in a single work step, wherein the coating can be drawn all the way into the back surface of the lining part given an appropriate fashioning of the mold. A complete surface enhancement thus occurred to the extent that it was desired. The completed lining part had high dimensional accuracy because a "free" drying process is no longer necessary. No material is wasted, since only the amount of material required for the coating needed to be employed. In the method of the earlier proposal, the material is preferably employed for the coating that liquifies below the spontaneous ignition temperature of the blank. This is not only practical for manufacturing reasons; on the contrary, a later separation of the coating and blank and, thus, a recycling can also be possible. A liquified coating, for example, can be removed from the blank simply by dripping off or under the influence of a centrifuge.
The method of German Published Application No. 41 24 294 has definitely proven itself. However, the manufacture of a reinforcing layer, which is introduced into the injection mold together with the blank in a pre-shaped condition in the known method, presents difficulties and is relatively complicated.